No! You have just been (choosing) the wrong mates for yourself.
There is no such thing as being "too anything" if that is what your mate wants in their mate! Ultimately if you or your mate has to change their (core) being in order to make a relationship work it usually means you have chosen the wrong mates for yourselves.
Very few people walk around looking for someone to "change" them. The vast majority of us want to be loved, appreciated, and accepted for who we are. The number one cause for breakups/divorces is selecting the "wrong" mate for ourselves.
Once you figure out what traits (you want or need) in a mate you must have the discipline to stick to your own "shopping list" when choosing a mate. This will require doing some serious introspective thinking on your part. People who skip this step often allow "impulsive connections" and "happenstance" to dictate their relationship choices.
Never separate your mind from your heart when making relationship decisions. The purpose of the mind is to protect the heart.
"Never love anyone who treats you like you're ordinary"
- Oscar Wilde
Lastly we live in a time where there are about 20 different birth controls for women. You need to figure out why you have had two "accidental" pregnancies. Now that you're a mother your top priority has to be getting training or establishing a career path that will provide for you and your child. Not only will this make you more financially independent it will also raise your confidence and self-esteem. Focus on what you have and not what you don't have.
Since you did not mention your age the following may or may not apply to you. If a woman is in her 20s looking to settle down or get married odds are against her finding a man (her age) who is "ready" to take that plunge. Most guys look at their 20s as a time to "play the field", party/hang out with their buddies, or establish careers. The last thing on their mind is becoming their parents!
The thought of getting married, having an "instant family", and signing a 30 year mortgage is like watching their lives flash before their eyes! A woman in her 20s looking for those things might do better to date men who are in their 30s and have never been married.